The present invention generally relates to vehicle or traffic speed controls and more particularly to an improved speed bump device.
Speed bumps are frequently embedded in roadways, such as in access lanes to and from residential and school areas, parking lots and the like so as to discourage or prevent the use of vehicles at high speed. Most such speed bumps are merely spaced rubber, steel, asphalt or concrete bars or the like placed on the road surface and, accordingly, are subject to wear. Moreover, they do not retract, so that even slow moving vehicles are jolted by passing over the bumps.
Certain other speed bumps have been devised which have bumps that can be retracted or raised, as needed, either by a tool or by a remotely operated hydraulic ram. Another mechanism, which is disclosed by U.S. Pat. No. 4,974,991, is a speed bump which automatically lowers when contacted by a vehicle wheel traveling at a lower than prescribed speed. Unfortunately, the design disclosed by the '991 patent for the automatic speed bump requires the presence of a rectangular hole in the roadway. While such a hole would generally not be a hazard to most automobiles, it could pose a significant hazard to others who use roadways, i.e., pedestrians and bicyclists. In addition, such a depression in a roadway will necessarily collect debris and standing water which would likely challenge the mechanical integrity of the automatic speed bump. Accordingly, there remains a need for an improved speed bump which can selectively allow slow moving vehicles to pass thereover smoothly without a bump while causing rapidly moving vehicles to suffer a bump.